Assessing Phase Stability in High-Entropy Materials by Design of Experiments: The Case of the (Mg,Ni,Co,Cu,Zn)O System

In this study, we aimed to explore the phase stability of high-entropy oxides (HEOs) beyond their conventional equimolar composition, which presents the maximum configurational entropy. This task is challenging due to the large number of compositional parameters involved. We used the design of experiments as a strategy to investigate the compositional range of stability of the rock salt (RS) structure in the (Mg,Ni,Co,Zn,Cu)O quinary system, featuring the prototypical HEO Mg0.2Ni0.2Co0.2Zn0.2Cu0.2O. Our study revealed that the chemical nature of the RS-native oxides (NiO, MgO, and CoO) significantly affects the phase stability of the RS-HEO, suggesting that the HEO stability is not solely governed by the balance of configurational entropy and enthalpy of mixing. In addition, a single high-entropy phase can be achieved on a wide out-of-equimolar set of compositions, thereby broadening the compositional range that should be explored in the search for innovative materials with unique properties and applications

Molecular formula of exjade and speciation plots of its variously protonated forms.

<p>Molecular formula of exjade and speciation plots of its variously protonated forms.</p

Molecular formula of deferiprone and speciation plots of its variously protonated forms.

<p>Molecular formula of deferiprone and speciation plots of its variously protonated forms.</p

Speciation of different simulated conditions in the presence of the three different chelators.

<p>Total concentrations of ligands, iron, zinc and copper (μmol/L) in species calculations are reported in columns 2 to 5, while the concentrations (μmol/L) of calculated complexed species (disregarding minor species) are reported in the remaining columns.</p

Adsorption of the Prototype Anionic Anthraquinone, Acid Blue 25, on a Modified Banana Peel: Comparison with Equilibrium and Kinetic Ligand–Receptor Biochemical Data

The adsorptive behavior of dye Acid Blue 25 (AB25) on the banana peel is studied with two objectives in view. First, from an environmental point of view, AB25 is considered a model of the anionic dyes, and the banana peel is a quite abundant agricultural waste which can be reused as adsorbent. Second, and on account of the recent research on possible applications of 1-aminoanthraquinone derivatives in pharmacological research, physicochemical studies on the interaction of AB25 anionic prototype and related dyes with different kinds of biomass surfaces can be useful in the basic modeling studies on the antagonist-P2 receptor interactions carried out by different researchers with 1-aminoanthraquinone dyes. A careful analysis of the acid–base properties of the biomass provides the number of weak acid groups, that was found to be 0.288(7) mmol g^–1 for modified banana peel in 0.1 M KNO₃. An uptake capacity value of 0.215(13) mmol g^–1 is obtained when data from batch experiments are fitted to sorption isotherms. Specific surface is calculated and compared with other biosurfaces. Kinetics of the process allows calculating an intraparticle diffusion coefficient, <i>D</i>_i, of 0.331(1) × 10^–13 m² s^–1. Desorption and column experiments demonstrate the feasibility for an application for AB25 recovery in remediation. Finally, a comparison with thermodynamic and kinetic data from receptor–ligand studies is also carried out

Protonation and complex formation constants for DFO, DFP and DFX with iron(III), copper(II) and zinc(II) from literature.

<p>Protonation and complex formation constants for DFO, DFP and DFX with iron(III), copper(II) and zinc(II) from literature.</p

Daily doses of iron chelators.

<p>Daily doses of iron chelators.</p

Molecular formula of deferoxamine and speciation plots of its variously protonated forms.

<p>Molecular formula of deferoxamine and speciation plots of its variously protonated forms.</p